Shoe last turning lathe



Jan. 14, 1958 H. s. CLAUSING 2,819,741

SHOE LAST TURNING LATHE Filed Dec. 29. 1954 2 Sheets-Sheet 1 I z a 5316') 3a l 56' u Jan. 14, 1958 H. G. CLAUSING 2,819,741

' SHOE LAST TURNING LATHE Filed Dec. 29, 1954 2 Sheets-Sheet 2 IN V ENTOR.

lie m" a Clauu'n BY 7 j United States Patent SHOE LAST TURNING LATHEHenry G. Clausing, Portsmouth, Ohio, assignor to Vulcan Corporation,Portsmouth, Ohio, a corporation of Ohio Application December 29, 1954,Serial No. 478,353

Claims. (Cl. 1427) This invention relates to an improvement in copyinglathes for making shoe lasts and is particularly directed to a latheadapted to finish turn lasts completely over their toe portions.

The production of lasts has presented many problems to the lastmanufacturer, not the least of which was the finish turning of lasts ina lathe to produce accurately formed lasts that conformed in detail tothe model especially at their toe portions. Heretofore lasts turned in alathe had to be brought to a final form by a hand finishing operationthat depended for its accuracy upon the skill of the last maker to sightthe model and bring the same effect into the finished last. Thus eachlast differed slightly from other lasts turned from the same model lasteven when finished by the same skilled worker.

It is therefore an object of this invention to provide an improvedcopying lathe for making lasts which produces an accurately finishedarticle by a single operation in that it feeds the work block past alaterally vibratile, high speed cutter with a longitudinal, heel-totoemovement; said lathe having a change speed device made operative as thetoe portion of the work approaches the cutter to effect a relativelyslow translatory movement of the work relative to the cutter duringformation of the toe which accurately reproduces and finishes the toecontour of the last.

Another object of the invention is to provide a two speed work blocktranslating carriage which in cooperation with a model controlled highspeed, vibratile cutter will finish turn, in one operation and in aminimum of time, a shoe last having relatively abrupt irregularities atthe toe portion as compared with other portions of its profile.

Other objects of this invention are to provide a copying lathe of thecharacter heretofore described that will eliminate the necessity for thehand finishing operation of lasts; which will produce a uniform toe; andwhich involves a relatively simple attachment that may be installed onpresent day lathes to convert them to the production of shoe lastsaccording to this invention.

The invention consists in the details of construction and in thecombination and arrangement of the several parts of my improved copyinglathe whereby the foregoing advantages are attained; as will behereinafter more fully set forth.

In order that my invention may be clearly understood I will proceed to adescription of the same with reference to the accompanying drawingswhich illustrate its preferred embodiment and wherein:

Fig. 1 is a fragmental, front elevational view of my copying lathe forproducing shoe lasts, including the complete toe portion whicheliminates hand finishing.

Fig. ,2 is a fragmental, side elevational view of the lathe shown inFig. 1.

Fig. 3 is a fragmental, top plan view of the lathe as shown in Fig. 2.

Fig. 4 is an enlarged section taken on line 4-4 of Fig. 2.

Fig. 5 is an enlarged section taken on line 5-5 of Fig. 2.

As shown in the drawings my improved lathe comprises a base 8 upon legs99, said base supporting a pair of spaced columns 10 and 11 securedtogether at their upper ends by a shaft 12. The shaft pivotally supportsa vibratile, laterally shiftableswing frame 13 that depends therefromand holds a shoe last model 14 and a work block '15 mounted thereon inaxial spaced relationship, suitable instrumentalities such as supportingcenters or dogs '16 and cooperating driving means 17 being provided forthe carriage to effect continuous and simultaneous rotation, at the samespeed, of the model and the block as is usual in the art. It will benoted that the supportingcenter for the model last toe portion is oftheunderdog type in that it is connected to the sole portion of themodel leaving the entire toe upper free to be reproduced on the workblock.

Power is supplied thedriving means 17 by pulley and belt arrangement 18connected to a main power shaft 19 that is journalled in bearings fixedto the rear of the lathe base 8. The base has a longitudinally extendingdovetail feather 20 by which a carriage 21 is guided for translatorymovement with respect to the swing frame 13, said carriage holding amodel wheel 22 and a cutter 23, the latter being continuously rotated athigh speed by a motor 24 fixed on the carriage and connected to thecutter spindle by a belt and pulley drive 25.

It will therefore be understood that the laterally shiftable swing frame12 and the translatory carriage 21 provide cooperating means,longitudinally displaceable to one another, for moving the modelcontrolled cutter 23 from heel-to-toe with respect to the work block tothe end that the heel and the adjacent portion of the toe may be firstturned on the work block and the terminal portion of the toe formed onthe last as the final phase of the turning operation. A means foreffecting translatory movement of the carriage in a last heel-to-toedirection takes the form of a lead screw 26 journalled against axialmovement on the front of the base 8 by bearings 27 and 28. One end ofthe screw extends beyond a side of the base and has a pulley 29 keyed,or otherwise fixed to it, whilst a follower 30 projects from thecarriage and has an internally threaded bore 31 formed therethrough forcooperatively receiving the screw 26. As best shown in Fig. 2 the leadscrew pulley 29 is driven from the main shaft 19 by a two-speed powertransmission comprising a split pulley 32 fixed on said shaft and anendless V-belt 33 running over both of said pulleys and normally havinga pair of parallel reaches 34 and 35 extending therebetween.

There willnow be described the preferred control for automaticallydiminishing the translating speed of the carriage as the cutterapproaches and passes through the toe portion to be formed on the workblock. With particular reference to Figs. 3,and 5 it will be noted thatthe split pulley 32 comprises two opposed, circular sections 36 and 37formed with concentric hubs 38 and 39, respectively, for slidablyreceiving the main .power shaft 19; the hubs being secured againstrotation on the shaft by a key 40, and against inward movement by ashoulder integral on the shaft. The sections 36 and 37 each have anoutwardly flaring peripheral flange 41 and 42, respectively, whichnormally engage the inwardly convergent faces of the V-belt 33 toprovide the high speed translatory movement for the carriage 21. Thenormal operative positions of the pulley sections is maintained by meansof an expansile spring 43 encircling the power shaft and bearing at oneend against the hub 39 of section 37 and engaging a washer 44 adjustablysecured on the shaft by a pair of lock nuts 45 threaded to said shaftend. A change speed arm 46 is pivotally mounted on the base '8 by apivotal connection 47, the outer end of said arm carrying a weight 48longitudinally slidable thereon and fixed in adjusted positions by a setscrew 49. An idler wheel 59 is rotatably mounted on an intermediateportion of the arm 46 by a journal bearing 51, said wheel being normallyheld out of engagement with the reach 35 of the V-belt 33 by a detentlatch 52 projecting from the base 8 and releasably supporting the arm 46in the normal position indicated in Figs. 1 and 2. As best shown inFigs. 1 and 4 the detent latch is slidably secured in an aperture 53formed through the base 8, its position being controlled by a crank 54having a pivotal connection 55 with the detent. This crank is rockablymounted at 56 to the base and has its upper end projecting through anopening 57 in the base and into the path of the leading end of thecarriage 21. The upper extremity of the crank has an adjustable carriageengaging stop in the form of a set screw 58, the crank being urgedtoward normal operative position by an expansile spring 59 bearing atone end against the upper end of the crank and at its other end againsta lug 60 formed on the base. With reference to Fig. 4 it will be notedthat the underside of the projecting end of the latch detent 52 istapered at 61 for engagement with the arm 46 when the latter is raisedto depress the detent latch against the action of the spring urged crank54 and allow return or" the arm to its supported operative position uponthe detent.

For the purpose of illustration it will be assumed that a lastcorresponding to the model 14 is to be formed from the work block 15 andthat said model and block are supported for rotation on the vibratileframe 12. To this end a suitable model 14 is supported by underdog 16 inthe frame in a well known manner. It will also be assumed that suitabletension has been placed on the spring 43 to just hold the sections 36and 37 of the split pulley 32 together for normally driving the carriagetranslating pulley 29 through its V-belt connection therewith. Furtherthe proper position of the adjustable carriage engaging set screw 58 isdetermined so that the detent will be tripped as the cutter 23approaches its toe end portion forming position with respect to the workblock 15. With the carriage 27 in the position indicated in Fig. l thelathe is put in operation by starting the motor 24 to continuouslyoperate the cutter 23 and by connecting a pulley 62 on the main shaft 19with a source of power (not shown). Rotation of the main shaft 19 willcause simultaneous rotation of the last model 14 and work block 15 andalso translatory movement of the carriage 21 by rotating the lead screwthrough the pulleys 32 and 2) that are operatively connected by theV-belt 33. This drive connection for translating the carriage isreferred to as the high speed connection by reason of the fact that thebelt engages in the peripheral groove of the split pulley 32 formed bythe flared ends of the closely spaced apart pulley sections. As thecutter 23 approaches to and passes through the end of the toe formingstep in the turning process the carriage 21 engages with the set bolt 58thus rocking the lever .55 on the pivot 56 against the operation of thespring 59 and withdrawing the detent latch 52 from beneath the arm 46allowing the arm to fall by gravity. This action engages idler wheel 50upon the reach 35 of the V-belt 33 and as the force of the weight 48exerted on the reach through the pulley 50 will overcome the tension ofspring 4-3 on the split pulley 32, the pulley sections 36 and 37 spreadapart so that the belt will seek and take up a smaller effective radiuson the split pulley as indicated in dotted lines in Fig. 2. This actionwill reduce the speed of the pulley 29 and hence the translatorymovement of the carriage to permit a very fine turning pitch for thelathe cutter relative to the work as the terminal end of the toe of thelast is being formed from the work block. It will be noted that duringlathe operation on the toe portion under relatively slow translatoryspeed of the carriage, the cutter, the work and the model rotatingspeeds remain the same as when the lathe operation was progressing atthe high carriage translatory speed thus providing a finished surface onthe toe portion which requires no further hand finishing operation.After the last turning operation is completed the carriage is returnedto the initial position shown in Fig. 1, it being necessary to raise thearm 46 past the detent 52 to again return it to the normal operativeposition shown in Fig. 2.

What is claimed is:

1. In a machine for copying shoe lasts the combination of a laterallyshiftable means for holding a model and a work block, a longitudinallyshiftable means for holding a model wheel and cutter, said two meansbeing longitudinally displaceable to one another in a direction suchthat the cutter moves from heel-to-toe with respect to the work block, atranslating device for effecting said longitudinal displacement, poweractuated drive means for the device, a change speed element interposedbetween the drive means and the device, and a control in the path of thelongitudinally shiftable means for holding the model and work block,said control being connected to the change speed element and madeoperative as the cutter approaches the toe portion of the work block foractuating the change speed element.

2. In a shoe last turning lathe the combination of a model wheel andcutter carriage, a model and work block carriage including constantlyrotating instrumentalities therefor, traversing means for providingrelative movement between the carriages that is displaceable in aheelto-toe direction of the work block with respect to the cutter, poweractuated drive means for the traversing means, a change speed deviceinterposed in the drive means, a control in the path of one of thecarriages, and means for operatively connecting the control to thechange speed device, said control being made operative as the cutterapproaches the toe portion of the work block for actuating the changespeed device.

3. In a shoe last turning lathe the combination of a first means holdinga model and work block for rotary movement, a second means for holding amodel wheel and a continuously operated cutter, said two means beinglongitudinally displaceable to one another in a direction such that thecutter moves from heel-to-toe with respect to the work block, atranslating device for effecting said longitudinal displacement, powermeans for driving the model and block and the translating device inunison, a change speed element interposed between the power means andthe translating device, a control connected to the change speed element,and means for mounting the control in the path of the said second meansand actuated thereby when the cutter approaches and forms the terminalportion of the last toe for actuating the change speed element.

4. In a shoe last turning lathe the combination of a first means forholding a model last and a work block including constantly rotatinginstrumentalities therefor, a second means for holding a model wheel anda continuously rotated cutter, said two means being longitudinallydisplaceable to one another in a direction such that the cutter movesfrom heel-to-toe with respect to the work block, a rotatable translatingdevice for elfecting said longitudinal displacement, a main power shaft,:1 drive connection between the main shaft and the instrumentalities, atwospeed power transmission connecting the main shaft to the translatingdevice, and a normally inoperative twoposition control connected to thetwo-speed power transmission, said control being interposed in the pathof the second means and actuated thereby when the cutter approaches andforms the terminal portion of the last toe.

5. A shoe last turning lathe as set forth in claim 4 characterized bythe fact that the two-position control supports a weight in one positionand releases said weight in its other position and that the transmissionincludes a belt driven pulley having a pair of belt engaging sectionsspring urged together and separable when a predetermined tension isapplied by release of the weight upon the belt to reduce the effectivedrive radius of said pulley with respect to the belt.

References Cited in the file of this patent UNITED STATES PATENTS1,798,926 Black Mar. 31, 1931

